The present invention pertains to treating animal, including human, waste to reduce stench and septicity. More specifically, the present invention is for highly effective, safety improved chemical compositions and methods for treating body wastes to reduce stench and septicity which can replace certain aldehydes.
Aldehydes are known to be effective primary treating aids, but exhibit significant degrees of toxicity in the free state, rendering them unsafe for handling and use. Formaldehyde and glutaraldehyde have long been known to be effective body waste treating aldehydes for reducing stench and septicity. Both are toxic aldehydes existing under all ambient conditions in both liquid and volatile form. The vapors from both aldehydes are toxic to life upon ingestion, contact, and when breathed. Depending upon concentrations and means of contact, injuries can range from dermatitis to death.
Body wastes from humans and other animals are comprised of biochemicals formed with, from, and of food created as a result of food consumption and consequent metabolic activities. Body wastes are essentially of 4 types: Glandular by-products, respiratory by-products, alimentary by-products and water balance by-products.
The present invention is specifically concerned with compositions and methods for reducing stench and septicity of fecal and urinary wastes from human beings and other animals. Compositions and methods for controlling stench and septicity for glandular and respiratory by-products are anticipated only inasmuch as they might occur with primary body wastes comprised of fecal and urinary excreta. Among other matter, fecal and urinary wastes include products of reacted digestive matter such as acids, enzymes and digested foods (digestive liquids and solids), varied microbiological species and their metabolites, volatiles and, sometimes, parasites and disease related matter.
Moreover, facilities utilized by persons to void wastes such as portable, ship, recreational vehicle, and commercial air transportation waste facilities are comprised of tightly sealed and small spaces which tend to easily become polluted with volatiles from collected wastes. This exposure is unhealthy for those who must use such facilities. Many products used today to reduce exposure to this unhealthy environment may accomplish substantial reductions in the typically uncontrolled pollutants. Unfortunately, the toxic nature of these products presents a significant danger to maintenance and other persons exposed to the products of equal or greater threat to health than the pollutants.
Due to the highly unpleasant nature of body waste products and their inherent malaesthetics and pathological potential, many workers have sought to find ways and means to effectively reduce or eliminate stench and/or septicity associated with them.
Indeed a variety of means have been developed both municipally and for specific dwellings which are more or less effective for controlling these wastes safely. In these instances plumbing is the major control feature. Plumbing permits the safe transport of such materials, including the associated volatiles, to central points of specialized processing where the material is stabilized and disposed. Municipal sewage processing, septic tanks and drain fields are examples of these facilities. Few, if any, persons related to the disposal of those specific body wastes are consequently ever exposed to the health hazards of those who use portable body waste receiving and containment facilities.
Many conditions exist where there is increased human exposure to wastes resulting through the necessity for handling or transferring body wastes such as from septic tanks and portable toilets, and such as those common to transportation, marine and recreational vehicles, and construction and event sites. The immediate environment of use for such systems is often noxious and highly unpleasant: for example, a publicly used portable toilet as found at camp grounds. Another problem is spills made during handling and transfers.
Many examples of prior art demonstrating an awareness and effort to resolve one aspect or another of the problems inherent to conditions described are known and are, in many cases, still in use.
Septicity as referred to in the present invention is the presence in body wastes of indigenous forms of fermenting and non fermenting organisms and microorganisms (both hereinafter referred to as microorganisms). These microorganisms constitute the basis of one of the ongoing major pathways of putrefaction or decomposition of body wastes. Many of these, along with infectious microorganism related to specific diseases or disease states, comprise the wide and diverse variety of pathogens which are to be found in association with body wastes. Parasites and other pathogens are encompassed by the term septicity as employed hereinafter.
Stench as referred to in the present invention relates to an unpleasant phenomenon associated with fecal and urinary body wastes, polluted air comprised of two characteristics simultaneously perceived but related to separate, distinct physical events; one of which is olfactory and the other of which is a trigeminal nerve response. The distinction, while little known and seldom differentiated even technically, is significant. As a rule, stench is a considerably more significant occurrence than just odor since, by definition, it is constituted of both an odor (usually but not always malodor) component and a highly reactive (as evidenced by pain) volatile chemical component. In general, odor volatiles per se may be characterized as pleasant or unpleasant, highly distinct, and perceivable in extremely low ranges of concentration. Moreover odor volatiles frequently do not exhibit any threshold of pain, regardless of the concentration. Many volatile molecules do possess both a pure odor character and a trigeminal factor. Trigeminally mediated volatiles are almost always highly reactive, usually polar, molecules which are perceivable in higher concentration ranges and which demonstrate a narrow difference, if any, between threshold of recognition and threshold of pain. Vanillin is an example of a odor molecule, amyl acetate of a composite odor/trigeminal molecule, and ammonia a trigeminal molecule.
Technically speaking ammonia (representing the simplest form of N R'; the principal molecule and moiety specie of body waste decomposition volatiles) is probably not an odor at all.i.e., it is sensed as a trigeminal response and not integrated via the olfactory mucosa to the rhinencephalon. Perception of ammonia is painful because ammonia, and many moieties of it, are destructive to the 5th cranial nerve which reports to the medulla oblongata, and is also destructive to mucosal and other tissues, such as the eyes.
Formaldehyde has long been used as a direct additive to body wastes. Formaldehyde is a very good sterilant and bactericide used within its limitations. Formaldehyde is known to be a very poor penetrant of biological matter and is consequently of somewhat questionable value as a microbicide under many conditions.
Formaldehyde (HCHO) is commercially offered as a 37% to 50% aqueous solution. Its properties: Strong pungent odor, yap d 1,067 (ait=1.000), at -20/4C yap d 0.815, bp -19C. It is a lachrymator, carcinogen, toxic by inhalation, and strong irritant. Threshold limit value (TLV): 1 ppm in air. LD.sub.50 orally in rats: 0.80 g/kg. Vapors are intensely irritating to mucous membranes. Skin contact may produce irritant dermatitis.
With Pseudomonas putida, the threshold concentration for toxicity of formaldehyde was determined in a cell multiplication inhibition test resulting in EC.sub.10 =14 mg/l after 16 hours' exposure. The test was performed with a 35% water dilution. Experiments with Pseudomonas fluoreszenz gave a threshold concentration for toxicity of 2 mg/l and 14 mg/l (inhibition of glucose degradation, inhibition of cell multiplication, 16 to 24 hour exposure). Under the same conditions, the threshold concentration for Escherichia coli was 1 mg/l. The respiration of activated sludge was not affected by formaldehyde up to 1,995 mg/l (highest test concentration) after 30 minutes' exposure.
Formaldehyde also exhibits significant activity with respect to reduction of stench from body wastes. Despite formaldehyde's poor penetrating qualities, it is effective against stench by both physical and volatile-to-volatile contact. Body waste stench treated with formaldehyde is dramatically, but not entirely, reduced. There are always characteristic, residual qualities of stench which seem unamenable to reduction by formaldehyde. This may not, but probably does, relate to the same functional characteristics which make formaldehyde a poor penetrant of body waste matter; i.e., it lacks adequate solventizing qualities to provide for adequate contact with microbes and stenchophoric elements inherent in the wastes. Formaldehyde reacts poorly, if at all, against lipidaceous moieties of any type. This includes those portions of protein breakdown products which contain lipids or carboxylic groups, as well as lipids per se, associated with body wastes. Upon the oxidative and enzymatic breakdown of lipids, fatty acids, which represent a very strong class of stench molecules, will be released. Also, many amines contain carboxylic groups which become freed with ammonia, or in association with amino nitrogen and sometimes sulfur volatiles, as nitrogen/fatty acid and nitrogen/sulfur/fatty acid complexes. These classes of stench molecules represent the majority of those associated with the decomposition of most protein/lipid containing biowastes, such as body wastes. Formaldehyde is not effective against lipids or fatty acids or fatty acid complexes. In liquid, solid or volatile form it is not lipid soluble and is not effective against these stench volatiles. Used alone, formaldehyde cannot fully meet the objects of the present invention, stench prevention or reliable reduction of septicity.
Despite the above limitations, for a great many years formaldehyde has been used with moderate effect in one form or another for purposes of reducing stench and septicity of body wastes. Chemical product reviews driven by environmental and health safety concerns over the past several decades have, however, made it clear that formaldehyde is a carcinogen. Its vapors are irritating and while long known to be toxic to human life, it is now also known to be a carcinogen. This, of course, does not mean that formaldehyde cannot, or should not, be used under any circumstances, but that uses should be altered to conform with that awareness of its toxic and carcinogenic nature, or alternatives should be sought. Any treatment for body wastes that would be likely to result in persons being exposed to fugitive formaldehyde volatiles should not be used. This is most particularly true where the fugitive formaldehyde could be trapped in an enclosed environment, such as a portable toilet module, recreational vehicle and the like, where human beings will be certain to visit. Moreover, it should not be used even when the fugitive formaldehyde is not likely to be concentrated, such as where a user, worker or other person may be chronically exposed. For example when septic tanks are pumped, portable toilets are emptied, or marine or recreational vehicles are used or when formaldehyde liquids are openly poured into body waste receptacles.
One of many possible examples of common past use which should no longer be allowed is the use of formaldehyde containing solutions in portable toilets. Since the portable toilet is a repository for body wastes of given capacity, a charge of formaldehyde-containing agent is made which is adequate to control that capacity. This, of course, means that if the treatment dose to reduce stench over the capacity cycle has been calculated accurately, there will at all points in time be fugitive formaldehyde volatiles in the portable toilet until the instant capacity has been achieved when, presumably, there would be equilibrium between body waste stench and formaldehyde. The problem is, of course, that proper treatment of a portable toilet to prevent stench means that every single person using the portable toilet saved from the malaesthetics of stench is guaranteed some exposure to formaldehyde vapors. Moreover workers who clean, transport and maintain such equipment can be chronically exposed during formaldehyde handling, make up and treatment, walk-in testing and inspection, and upon clean-up and disposal cycles.
In recent years many manufacturers of products for use with body wastes, being aware of the problems with formaldehyde, have gone to glutaraldehyde as an alternative. While glutaraldehyde does have the advantage of a lower vapor pressure, and is considered somewhat less toxic than formaldehyde, it still suffers from all of the same disadvantages of formaldehyde.
Glutaraldehyde (C.sub.5 H.sub.8 O.sub.2) has a vapor pressure of 17 mm (20C) and liq. density of d 0.72. It is an irritant and carcinogen. TLV ceiling is 0.2 ppm in air. LD.sub.50 of 25% solution orally in rats: 2.38 ml/kg; by skin penetration in rabbits: 2.56 ml/kg.
Addition of formaldehyde and glutaraldehyde to body wastes can result in some reduction of stench. The mixture can react volatile to volatile with amino nitrogens and freed ammonia. Employed under conditions of high moisture and mechanical agitation, the mixture can influence substantially the reduction of ongoing stench from microbial and indigenous digestive activities upon body wastes. If agitated adequately with body wastes, formaldehyde is not only a powerful microbicide but also can arrest the decomposition of proteins and all species of protein breakdown products, including amino acids. The form of reaction involves strong cross bonding as well as other reactions with proteins and derivative products including peptides, amino acids, urea nitrogen and ammonia. The bonds are strong and resistant to decomposition, so stability can be quite good. Despite its deficiencies, used singularly formaldehyde has been, and would remain, a powerful basic control agent for combined stench and septicity control of body and other bioorganic wastes where proteins and protein products are prominent. Unfortunately, the on-going use of either formaldehyde of glutaraldehyde cannot be justified and should not be continued in view of its significant and clear threat to human health.
Quats can be useful for cleaning septic body wastes from surfaces and consequently may be employed advantageously, as may other surfactants and microbicides, in an accessory capacity to methods and products of the present invention. Quaternary ammonium products (quats) have long been used as surfactants of choice for cleaning biological wastes of all sorts and varieties, including body wastes. For controlling stench and septicity, they are inadequate and impractical under the necessary use conditions discussed herein. Quats and other cationics are insufficiently concentrated for the uses discussed herein. The stench-controlling factor associated with quats is not related to direct action with stench volatiles or even non-volatile stench precursor molecules. Quats act only on contact and not volatile-to-volatile, so they cannot react at all with stench molecules already present.
Two pathways of stench formation from ongoing breakdown of food molecules exist. Components of foodstuffs, such as polypeptides and amines, serve as reservoirs of NH.sub.3 and sulfur molecule moieties which, when released through breakdown, form the bulk of fundamental volatiles associated with ongoing generation of body waste stench. One path whereby stench is generated from components such as amines, for example, is due to on-going decompositional effects of digestive factors incorporated during transit through the body, such as enzymes, acids, and microbes. The other path is continued decomposition with generation of stench by-products of metabolites resulting from active fermentation by indigenous and exogenous microbes.
In relatively high concentrations, and when intermixed with body wastes and adequate water as occurs during washing, quats can indirectly reduce stench by killing many of the microbes, and thereby reduce stench volatiles associated with that pathway of stench formation. Reduction of the microbes is equivalent to reduction in septicity.
Quats do not react directly with stench volatiles and do not prevent enzymatic or digestive acid decomposition. In high enough concentrations, quats can effectively reduce microbial populations which generate stench and are septic. However, quats are not effective under typical concentrations in use and conditions of use within the field of the present invention. For example, the addition of an equivalent measure of quats to formaldehyde in a portable toilet would reduce none of the volatiles associated with incoming body wastes, they would not react with stench molecules diffusing over time from the body wastes, they would at best represent only minimal, if any, effect or not prevent any measurable ongoing decompositionally generated stench molecules derived from ongoing artifactual digests, they would not prevent the continued diffusion through the body wastes of those stench molecules, and they would not achieve adequate contact without mechanical agitation with microbes underneath superficial body waste layers to prevent increased septicity and stench generated therefrom.
In short, the addition of quats under these typical conditions and circumstances would do little to reduce or prevent the formation of stench or septicity of body wastes. Under the given circumstances, quats are less able to penetrate than formaldehyde since they exhibit no significant vapor gradient effectiveness against stench molecules, microbes, fermentation metabolites, artifactual digests or byproducts from their ongoing activities. Provided adequate quantities are used to clean body wastes with other conditions being present such as copious water and mechanical agitation to provide contact and emulsification with body wastes, quats can achieve a small degree of effectiveness to control stench by indirectly preventing its formation from microbial fermentation. In conjunction with application under appropriate conditions, the concentration of quats to body waste determines effectiveness; and to the degree that microbes are killed, septicity and (up to a point) stench are reduced accordingly. Quats can be useful for cleaning septic body wastes from surfaces and consequently may be employed advantageously, as may other surfactants and microbicides, in an accessory capacity to methods and products of the present invention.
Added to body wastes, different metals can positively influence them both in terms of reduction of stench and septicity. As is well known, however, many metals are either toxic or undesirable additions even to body wastes due to environmental and public health concerns. Those of particular effectiveness for reducing stench and septicity are cations of all transition metals (with particular reference to copper, cobalt, molybdenum and iron) and the non transition metals (zinc, and to a much lesser degree, aluminum). At least one non-metal which under some circumstances acts similarly to the metals is boron, usually in the form of borax. All other effective metals are either too toxic or too rare for practical use based on current beliefs and availability. Soluble salts of those metals mentioned, however, are convenient products for treating body wastes.
The effects of metals added to body wastes in terms of stench reduction are incomplete, i.e., substantial stench remains which is unamenable to metal treatment. For example, iron in the form of iron sulfate does reduce the overall stench of raw sewage; however a significant portion remains. The remaining stench portion is different, having taken on a somewhat sweet, earthy, but still unpleasant, character. This is also true of zinc, copper and other metals when added to sewage and similar biologic substrates. These metals are thus inadequate treatments to eliminate the stench associated with most biologic substrates, including sewage.
Metals also suffer the same shortcoming as quats in terms of both possessing no vapor-to-vapor reactivity with stench that already exists in association with the substrate, and poor penetration without good mechanical agitation in a high water solvent solution. Metals can be effective microbicides but are usually considerably most effective against fungi and algae in terms of concentrations required to kill than they are against bacteria or viruses. In fact, little is known about the ability of metals per se with respect to affect on viruses. Against bacteria, much higher concentrations are required and some bacteria are more tolerant than others against the effects of metals. It is most probable that, to some extent, the killing ability of a metal is as much related to the nature of the salt or complex from which it is derived. The salt or complex may cause high or low pH's which can be instrumental in causing substantial and, if high or low enough, even total, microbial kills.
Metals in any combination are inadequate to control stench of most biological substrates including body wastes, and they play a limited role in prevention of stench generated from fermentation or from ongoing indigenous digestive generation of stench. At best metals can play only a very limited, if any, practical role in controlling or reducing septicity or prevention of ongoing generation of stench volatiles form biological substrates. At best, metals represent a means of immediate reduction in stench, though for only short durations, and by no means cause complete stench elimination. Metals cannot act against any stench vapors per se but seem to act to temporarily and partially block some borderline reactions, mostly with nitrogen moieties, which are occurring continuously at a point in the decomposition reaction where a portion of a solid is being released as a volatile. This almost certainly means that the metal is interfering briefly at the point source during the final decompositional breakdown of amino acids into basic ammonia and ammonia complexes. A primary interference with the ongoing evolution of volatiles is almost certainly a result of coordination of the metal and amino nitrogen and ammonia ligands being evolved. The coordination complexes formed are held by coordinate bonds until other decompositional factors overcome or replace the coordinate bond energy, at which time the volatiles are again released and the metals are complexed into more stable non-volatile complexes. To become effective in terms of playing a role in stench reduction, metals must be supported by conditions and other chemical species. The same is also true for volatile-to-volatile requirements to devolatilize stench molecules that already exist, and for reducing septicity which otherwise will continue to generate ongoing stench volatiles.
Metals can be very useful in a formulation for gaining initial rapid, short term control over freed ammonia and many, though not all, of the types of amino nitrogen complexes being generated from body wastes. The metals seem to have little influence on basic volatile groups generated containing amino sulfur or amino sulfur and nitrogens.